Including an imageResizing the image[img=100x50]https://www.bbcode.org/images/lubeck_small.jpg[/img]Making the image clickable (in this case linking to the original image)Resizing and adding meta information for the image[img width="100" height="50" alt="Lubeck city gate" title="This is one of the medieval city gates of Lubeck"]https://www.bbcode.org/images/lubeck_small.jpg[/img]

Including a youtube video

GBtYiLFH85A is the id of the video, you can see it from the url on youtube